Assertion (A): 100 is a perfect cube. Reason (R): A perfect cube has all primes in its factorisation appearing in groups of three. Which is correct?

**Step 1**: factorise into primes.
**Step 2**: group the prime factors into TRIPLES (three of the same).
**Step 3**: take ONE factor from each triple — their product is the cube root.

Example: ∛216. $216=2^3\times 3^3=(2\times 3{)}^3=6^3$. So ∛216 = 6.

Example: ∛13824. $13824=2^9\times 3^3=(2^3\times 3{)}^3=(8\times 3{)}^3=24^3$. So ∛13824 = 24.

If any prime doesn't form a complete triple, the number isn't a perfect cube.