Question

question 1
the algol paradox was resolved by
realizing that binary systems can become x - ray bursters.
discovering the chandrasekhar limit.
realizing that mass exchange can occur in close binary systems.
realizing that higher - mass stars use the cno cycle.

Explanation:

The Algol Paradox was resolved by understanding that mass - transfer can occur in close binary star systems. In Algol - like systems, the less massive star was more evolved than the more massive one, which seemed paradoxical. But when it was realized that mass exchange can happen in close binary systems, the paradox was resolved.

Answer:

realizing that mass exchange can occur in close binary systems.