All angles are right angles or a triangle has 4 sides.

a. Conjunction

b. Disjunction

c. Negation

d. Conditional

You know it's not a negation since nothing is being negated.

You know it's not a conditional because neither statement is reliant on the other to be true or false.

So, the answer must be a or b.

A conjunction implies there is an and which there is not. The solution then must be b. Disjunction, and it is indeed since disjunctions are the "or" statements of logic.