Please answer both questions answers only thanks

Constitutive heterochromatin A. is never packaged tightly. B is permanently packaged tightly. C. contains an increased number of genes. D can switch between heterochromatin and euchromatin states. Valproic acid was found to affect epigenetic expression of a variety of genes. How? A. By modulating histone acetylation B. By decreasing DNA methylation. C. By increasing DNA methylation D. By affecting SWI/SNF activity