Short answer. Yes. When the will itself gives you the right to choose, Article 942 lets you take whichever of the things you prefer. The testator has handed the decision to you rather than to the estate, so no heir, executor, or administrator can override your pick or force a particular item on you.
What the law says
Whenever the testator expressly leaves the right of choice to the heir, or to the legatee or devisee, the former may give or the latter may choose whichever he may prefer.
Civil Code, Article 942 — Right of Choice Given to the Legatee. Read the full provision →
The testator can hand you the choice
Article 942 speaks to the situation where a will offers you one of several things and, on its face, lets you decide. Whenever the testator expressly leaves the right of choice to the heir, or to the legatee or devisee, the former may give or the latter may choose whichever he may prefer. The key word is expressly. The testator must have plainly put the choice in your hands, not merely left the will silent about who chooses. Where he has done so, your preference controls: you look at the alternatives on offer and pick the one you want, and the estate must deliver that one to you.
Why the default rule is set aside
Normally, when a will leaves someone one of two things without saying who selects, the law presumes the person obliged to deliver the gift makes the choice. Article 942 is the exception that respects a testator who deliberately did the opposite. Because he chose to trust the beneficiary with the decision, the ordinary presumption steps aside. The heir charged with handing over the gift cannot substitute his own preference, hand you the less valuable option, or insist on splitting the difference. His role shrinks to carrying out whatever you decide within the range of things the will actually offered you.
Choosing within the will's limits
Your freedom runs only as far as the alternatives the testator named. The choice is between the things he actually offered — you cannot demand something outside the list or convert the gift into cash he never mentioned. Once you make your selection, you are settling which of the described things becomes yours. It is a genuine liberty of preference, exercised inside the boundaries the will draws. If the testator described two specific properties, you choose between those two; you do not get to reshape the gift into a third thing he never contemplated.
When the will is not clear about who chooses
Everything here depends on the will really giving you the choice in express terms. If the language is doubtful — if it is unclear whether the testator meant to let you pick or simply left the point open — you are no longer squarely within this rule, and a different default about who selects may apply instead. Disputes often turn on exactly that reading: whether the words used amount to an express grant of choice to the beneficiary, or whether the decision was left, by default, to the person burdened with delivering the legacy or devise.