Question

Astronomer: Most stars are born in groups of thousands, each star in a group forming from the same parent cloud of gas. Each cloud has a unique homogeneous chemical composition. Therefore, whenever two stars have the same chemical composition as each other, they must have originated from the same cloud of gas.

Which of the following if true would most strengthen the astronomer's argument?

• A. In some groups of stars not every star originated from the same parent cloud of gas.
• B. Clouds of gas of similar or identical chemical composition may be remote from each other.
• C. Whenever a star forms it inherits the chemical composition of its parent cloud of gas.
• D. Many stars in vastly different parts of the universe are quite similar in their chemical compositions.
• E. Astronomers can at least sometimes precisely determine whether a star has the same chemical composition as its parent cloud of gas.

Answer 1

The correct option is C Whenever a star forms it inherits the chemical composition of its parent cloud of gas.

Since each cloud of gas has a unique homogeneous chemical composition and stars are born in groups of thousand from these clouds of gas, it is evident that all these stars would inherit some chemical composition of its parents. Thus, option C best fits the context.