Angle and strain dimensions

Assertion (A): Angle and strain are dimensionless.

Reason (R): Angle and strain have no unit.

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

Both (A) & (R) are true but the (R) is not the correct explanation of the (A)

(A) is true but (R) is false

Both (A) and (R) are false

Both angle and strain are ratios of like quantities and are dimensionless. However, angle has a unit (radian), so R is false.