Since \( (2x + 3) \) is a factor of the polynomial function \( p(x) \), its multiplicity must be a non-negative integer. In polynomial functions, factors can have whole number multiplicities (1, 2, 3, ...) or zero, but never negative or non-integer multiplicities.
Given the options:
- 2 (valid)
- −1.5 (invalid)
- 1 (valid)
- 1.5 (invalid)
The possible multiplicities for the factor \( (2x + 3) \) are 2 or 1. Therefore, the valid responses regarding the multiplicity could be 2 or 1.