Which account is debited when recording the first semiannual interest payment for Robinson Company?

When recording the first semiannual interest payment for Robinson Company, cash is debited because the company is disbursing cash to pay interest on its debt obligations. In financial accounting, when cash is paid out, the Cash account decreases, which is recorded as a debit. This is a standard practice when a company pays interest to creditors or investors, reflecting the outflow of resources.

The other accounts mentioned do not accurately reflect the nature of the transaction. For example, Debt Investment would typically be debited when the investment is acquired, not when interest is paid. Interest Revenue would be credited in the books of the lender who earns the interest, rather than being debited in this case. An Unrealized Gain pertains to assets that have increased in value but have not yet been sold, which is not applicable in this context. Thus, debiting the Cash account accurately represents the transaction of paying out interest.