Assertion:After the appearance of oxygen in the atmosphere, methane and ammonia began to disappear.
Oxygen is involved in forming ozone layer.

Options

A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
B. Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion
C. Assertion is true, but Reason is false
D. Assertion is false, but Reason is true

Answer

B

Explanation

(b) With the addition of oxygen into the atmosphere, methane and ammonia began to disappear as they got oxidised forming carbond dioxide and nitrogen, respectively. These events ultimately transformed the ancient reducing, oxygen free atmosphere into the modern oxidising atmosphere with plenty of free oxygen. As more oxygen accumulated in the atmosphere. Ozone began to appear in the top layers. It developed in the presence of high energy radiations.