Answer : (D) Assertion is false, but Reason is true

Step 1 — Test the Assertion

The four bases in DNA are Adenine, Guanine, Cytosine and Thymine.

The four bases in RNA are Adenine, Guanine, Cytosine and Uracil.

Uracil belongs to RNA, not DNA. The assertion is false.

Step 2 — Test the Reason

DNA does undergo self-replication : the double helix unwinds and each strand acts as a template for building a new complementary strand, so one DNA molecule gives two identical copies. This is how genetic information passes to daughter cells.

The reason is true.

Step 3 — Conclude

Assertion false, Reason true $\Rightarrow$ option (D).

Step 4 — Remember the two differences between DNA and RNA