Correct Answer  Option 2 : 1.88 × 10
^{7} electrons
The correct answer is option 2) i.e. 1.88 × 107 electrons
CONCEPT:

Electric charge is a fundamental property of matter that causes the matter to experience a force when kept in electric and magnetic fields.
 There are two types of charges possessed by matter  negative charge and positive charge.
 The matter that is neither positive nor negative is said to be neutral.
 The electric charge of the matter comes from the charge carried by electrons and protons at the atomic level.
 The SI unit of electric charge is Coulomb (C).

Electric current is defined as the charge flowing per unit time.
It is given by:
\(I = \frac{q}{t}\)
Where I is current, q is the charge and t is the time.
CALCULATION:
Given that:
Current, I = 15 A
Time, t = 2 ms = 2 × 10^{3} s
Using \(I = \frac{q}{t}\),
The total charge passed to the person, q = It = 15 × 2 × 103 = 30 × 103 C
Charge of an electron = 1.6 × 10^{19} C
Number of electrons in 30 × 10^{3 }C = \(\frac{30 × 10^{3}}{1.6\; \times\; 10^{19}} = 1.88 \;\times\; 10^{17}\)