Although the chromatin structure of interphase and mitotic chromosomes is very compact, DNA-binding proteins and protein complexes must be able to gain access（通道） to the DNA molecule. Chromatin-remodeling complexes provide this access by
选项：

A: recruiting other enzymes.
B: modifying the N-terminal tails of core histones.
C: using the energy of ATP hydrolysis to move nucleosomes.
D: denaturing the DNA by interfering with hydrogen-bonding between base pairs.