Answer:
It would be both.
Step-by-step explanation:
The income effect is the effect on real income when price changes - it can be positive and negative. As price falls, and assuming nominal income is constant, the same nominal income can buy more of the good - hence demand for this (and other goods) is likely to rise.
The substitution effect is the economic understanding that as prices rise — or income decreases — consumers will replace more expensive items with less costly alternatives.