Answer:
4) the substitution effect
Explanation:
When a product's change in price (increase) directly influences the consumers to switch to lower-cost alternatives, it is called the substitution effect.
Usually, it is applicable for similar kinds of FMCG goods. Of course, personal spending power and consumer habits are of great importance too, but the substitution effect best describes what happens with the consumer choice when the price of a particular good increases.
The substitution effect describes situations when the product's price increases, but the spending power remains on the same level. If the change in spending power was the input for consumer choice, than it would be the income effect.