Answer: The correct answer is Option A.
Step-by-step explanation:
Atomic number is defined as the number of protons or number of electrons that are present in a neutral atom. It is represented by the symbol 'Z'
Z = Atomic number = number of protons = number of electrons
We are given:
Atomic number of chlorine = 17
So, number of protons = 17
Hence, the correct answer is Option A.