Counting chiral centers in molecule Q

Steps:

• Identify all carbon atoms in the structure of Q.
• For each carbon, check if it has four different substituents attached.
• Count only tetrahedral carbons meeting this criterion as chiral centers.
• Total the qualifying carbons to find the number.

Why D is correct:

• Molecule Q has 7 tetrahedral carbons, each bonded to four distinct groups, satisfying the definition of a chiral center.

Why the others are wrong:

• A: Underestimates by missing 3 chiral carbons in the side chains.
• B: Underestimates by missing 2 chiral carbons at the core.
• C: Underestimates by missing 1 chiral carbon in the functional group.

Final answer: D