At the instant when a string of casing being run from a MODU is landed in the well head, __________.

Correct Answer: Option C — the hook load (weight of the casing string) is removed from the MODU

When a casing string is landed in the wellhead, the load is transferred from the MODU's hoisting system (the hook) to the wellhead itself. Consequently, the hook load, representing the weight of the casing string, is removed from the vessel's derrick and supporting structure, affecting the vessel's stability.