The Figure Below Depicts Changes to the Amount of DNA

Multiple Choice

The figure below depicts changes to the amount of DNA present in a recipient cell that is engaged in conjugation with an Hfr cell. Hfr cell DNA begins entering the recipient cell at Time A. Assume that reciprocal crossing over occurs (in other words, a fragment of the recipient's chromosome is exchanged for a homologous fragment from the Hfr cell's DNA) .
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What process is occurring at Time C that is decreasing the DNA content?

A) crossing over
B) cytokinesis
C) degradation of DNA that was not retained in the recipient's chromosome
D) reversal of the direction of conjugation