What Is the Main Source of the Free Energy for the Mechanical

What is the main source of the free energy for the mechanical work performed by DNA helicases during DNA replication in our cells?

A) The hydrogen-bonding energy in the DNA double helix
B) Thermal energy in the nucleus
C) ATP hydrolysis by the helicase
D) The energy of SSB binding to single-stranded DNA
E) ATP hydrolysis by DNA topoisomerases