In a recipe, the amount of an ingredient like flour cannot be negative, and it should generally be a positive rational number represented in a meaningful way (for instance, whole cups or fractions of a cup).
Let's evaluate the options:
- −3: Negative number, not valid for cups of flour.
- 234: Positive whole number, valid.
- 47: Positive whole number, valid.
- \( \frac{4}{7} \): Positive fraction, valid.
- Square root of 3: While it is a positive number, it is irrational and not practical for measuring cups in a recipe.
Based on this analysis, the numbers that could be used to specify how many cups of flour should be used in a bread recipe are:
234, 47, and \( \frac{4}{7} \).
Since you can only choose one option, the best choice is 234, as it is a definite number of cups that can be used.