Question

while researching a topic, a student has taken the following notes: • stars form in a galaxy when gravity causes a massive cloud of dust and gas to collapse. • a galaxy in a phase of rapid star formation is called a starburst galaxy. • quenching is a process in which a galaxy loses star - forming gas. • a galaxy that no longer forms stars is called a quenched galaxy. • a quenched galaxy has entered the poststarburst phase. the student wants to explain what a quenched galaxy is. which choice most effectively uses relevant information from the notes to accomplish this goal? choose 1 answer: a before quenching, a starburst galaxy will form stars at a rapid rate. b when it becomes quenched, a starburst galaxy enters the poststarburst phase. c having entered the poststarburst phase, a quenched galaxy is one that no longer forms stars. d a starburst galaxy will lose star - forming gas and eventually become quenched.

Explanation:

To explain what a quenched galaxy is, we need a statement that directly defines it using the relevant notes.

• Option A talks about starburst galaxies before quenching, not defining quenched galaxies.
• Option B describes the transition of a starburst galaxy, not the definition of a quenched galaxy.
• Option C combines the two key points from the notes: "A quenched galaxy has entered the poststarburst phase" and "A galaxy that no longer forms stars is called a quenched galaxy", so it effectively defines a quenched galaxy.
• Option D explains the process of a starburst galaxy becoming quenched, not the definition of a quenched galaxy.

Answer:

C. Having entered the poststarburst phase, a quenched galaxy is one that no longer forms stars.