Step 1: Find the key idea in the sentence.
The sentence says he was magnanimous and his benevolence made him give to charity. Both words point to generosity, kindness, and a large-hearted nature. We need the word that means the opposite of this generous spirit.
Step 2: Check each option.
Option B, cruel, describes harsh or hurtful behavior, which is a stronger and different idea than simply being ungenerous. Option C, snobbish, refers to looking down on others, not to withholding generosity. Option D, tyrannical, describes harsh, unjust rule, again a different quality from generosity's opposite.
Step 3: Pick the direct opposite.
Option A, mean, directly means stingy or ungenerous, the exact opposite of magnanimous and benevolent.
Final Answer:
The direct opposite of generosity here is mean, so option A is correct. \[ \boxed{\text{A}} \]