Sunil was buying tickets at the counter when suddenly he noticed a lady’s purse lying on the floor.

The correct answer is A. Reticule.

A reticule is a small bag or pouch, typically made of fabric or leather, that is carried by women. It is often used to carry money, keys, and other small items.

The other options are incorrect because:

• A parasol is a small umbrella that is used to protect oneself from the sun.
• A vestibule is a small entrance hall or lobby.
• A veil is a piece of fabric that is worn over the head or face, typically by women.