Which of the following is one of the four primary offensive tasks?

Movement to contact is indeed one of the four primary offensive tasks in military operations. This task involves maneuvering forces to locate and assess the enemy's position before engaging them in combat. The objective of movement to contact is to initiate contact with the enemy while retaining the flexibility to react to the enemy's actions and to exploit opportunities as they arise. This is fundamental in gaining situational awareness and determining the enemy's strength and capabilities, thereby informing subsequent tactical decisions.

This task is particularly a precursor to other offensive operations, allowing commanders to seize the initiative and dictate the terms of engagement. It often involves elements of reconnaissance and can lead into other offensive actions, such as attacks or exploitation depending on the enemy's disposition and the overall strategy.

The other options do not represent primary offensive tasks. Defense, for instance, is a separate category of military operations focused on protecting and securing an area. Logistics refers to the support and supply functions necessary for sustaining military operations but is not an offensive task itself. Communication, while essential for coordinating actions and conveying orders, does not constitute a tactical offensive task in the same way that movement to contact does.