Consider the following differences between heterochromatin and euchromatin and choose the correct answer:
1. Heterochromatin stains deeply while euchromatin stains less deeply
2. Heterochromatin is late replicating while euchromatin replicates during the early stage of the S phase
3. Heterochromatin does not become acetylated but euchromatin takes up acetic acid on its histone during interphase
4. The crossover frequency is more in heterochromatin than in euchromatin

A. Only 1, 2 and 3 are correct

B. Only 2, 3 and 4 are correct

C. Only 3 and 4 are correct

D. 1, 2, 3 and 4 are correct

Answer: Option A