Assertion(A): The RNA of the viroid is of low molecular weight.
Reason(R): This RNA is able to cause neurological diseases in humans.
Choices for Assertions and reasons:
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.