"Rectitude" refers to moral integrity, honesty, and correctness of behavior or judgment. It describes a person who acts rightly and honorably. The question asks for the option that shares this sense.
"Integrity" is the only option that reflects the moral correctness carried by rectitude.
Let's summarize:
So the correct answer is "Integrity."
If the price of a commodity increases by 25%, by what percentage should the consumption be reduced to keep the expenditure the same?