Assertion (A): If a die is rolled, the probability of getting a number greater than 6 is $\dfrac{1}{6}$.

Reason (R): There are six possible outcomes when rolling a die, {1, 2, 3, 4, 5, 6}.

1. (A) is true and (R) is false.

2. (A) is false and (R) is true.

3. Both (A) and (R) are true and (R) is the correct explanation of (A).

4. Both (A) and (R) are true but (R) is not the correct explanation of (A).

When a die is rolled,

Total number of possible outcomes = 6

S = {1, 2, 3, 4, 5, 6}

Let E be the event of getting number greater than 6,

Number of favorable outcomes = 0

P(E) = $\dfrac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \dfrac{0}{6} = 0$.

Assertion (A) is false.

There are six possible outcomes when a dice is rolled,

S = {1, 2, 3, 4, 5, 6}

Reason (R) is true.

(A) is false and (R) is true.

Hence, option 2 is the correct option.