The correct answer is A) The T-handle is rotated. During engine operation, the illustrated strainer element is cleaned by rotating the T-handle. This allows the strainer to be backflushed, clearing any debris or contaminants that have accumulated in the screen. This method of cleaning the strainer element is preferred during engine operation, as it can be done without disassembling the housing or removing the entire element. The other options are incorrect because they describe more involved cleaning methods that would typically be performed during scheduled maintenance, rather than during normal engine operation.