What is the correct configuration for a straight and level flight at heading 135 degrees?

For a straight and level flight at a heading of 135 degrees, the configuration must maintain steady altitude and direction without any pitch change or banking. This means that the aircraft is neither climbing nor descending and is also not turning. Maintaining straight and level flight at a specific heading, in this case, 135 degrees, requires that the aircraft remains in a consistent path without deviation in altitude or course.

This option correctly reflects the fundamental principles of straight and level flight. When an aircraft is in this state, its attitude and rotational position must be stable, meaning the nose is not pitched up or down and the wings are level relative to the horizon. It’s crucial in aviation to ensure that the flight path remains unaltered to safely reach the destination.

The other options either describe conditions that indicate a climb or descent, a turn, or an incorrect heading, which violate the definition of straight and level flight necessary for a precise operation at the specified heading of 135 degrees.