Question

Your little sister wants a kitten. Your father says that if he lets her get a kitten, next she will want a pony, and then an elephant. Which fallacy does this commit?

Answer 1

This is known as slippery slope reasoning.

Step-by-step explanation:

According to Wikipedia

A slippery slope argument, in logic, critical thinking, political rhetoric, and caselaw, is an argument in which a party asserts that a relatively small first step leads to a chain of related events culminating in some significant effect. The core of the slippery slope argument is that a specific decision under debate is likely to result in unintended consequences. The strength of such an argument depends on whether the small step really is likely to lead to the effect. This is quantified in terms of what is known as the warrant. This type of argument is sometimes used as a form of fearmongering in which the probable consequences of a given action are exaggerated in an attempt to scare the audience. However, differentiation is necessary, since, in other cases, it might be demonstrable that the small step is likely to lead to an effect.