A question of fact would be:
A) does overeating cause obesity?
B) is small beautiful?
C) should all people have equal opportunities?
D) is procrastination a bad habit?

  A) does overeating cause obesity?

Explanation:

Terms in all of these questions often have fuzzy definitions, so it is often a matter of judgment whether a particular condition is or is not included in the discussion.

The question most likely to be considered a question of fact is ...

  A) does overeating cause obesity?

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"Overeating" and "obesity" can be objectively defined, even if the causal relationship is less easy to establish.

"Beautiful" is usually a matter of opinion, and cannot be considered a matter of fact.

"Equal opportunities" is exceptionally difficult to define considering the range of personalities and abilities that may be offered a given opportunity. This is another term that is more a matter of opinion than of fact. Whether something "should" or "should not" be provided is, likewise, a matter of opinion (or personal philosophy or religion).

"Bad habit" is another descriptor that is difficult to say is a matter of fact. Whether something is "good" or "bad" depends on the goal, and the effect of procrastination depends on the circumstances.

do you need with anything?