Final answer:
The crossing is the intersection of the nave and transept in a cruciform church, centrally located where both architectural elements meet, forming a cross shape symbolic in Christian architecture.
Step-by-step explanation:
The intersection of the nave and transept in a cruciform church is known as the crossing. This architectural feature is pivotal in the cruciform layout, bearing resemblance to the form of a cross, which is central to the Christian symbolism. The crossing is typically found at the center where the nave (the main aisle of the church that extends from the entrance to the altar) and the transept (the arm of the church that runs at a right angle to the nave) meet. The other options given, such as the chancel, apse, and aisle, represent different parts of the church layout. The chancel is the space around the altar, including the choir and the sanctuary, the apse is the semicircular or polygonal termination to the choir or nave, typically at the eastern end, and the aisles are the spaces parallel to the nave, separated from it by columns or piers.