The word "few" refers to a number of an object, but the exact value is not known. An indefinite numeral adjective gives an idea of how many (number) of a given noun, but the exact value is not specified. Hence, option B is the correct answer.
Option A is incorrect, as a definite numeral adjective refers to a definite value, a number.
Optio C is incorrect, as a distributive adjective refers to individual members or a group of a given noun.
Option D is incorrect, as a demonstrative adjective tells which noun we want to refer to.