How many circular leveling bubbles are present in the antenna transceiver group?

The correct choice indicates that there are four circular leveling bubbles present in the antenna transceiver group. This is important for ensuring accurate alignment and leveling of the antenna system, which is crucial for optimal performance in air defense operations. The leveling bubbles allow operators to determine if the antenna is positioned correctly, ensuring that the radar system covers the desired sector and accurately detects or tracks aerial threats.

Having multiple leveling bubbles provides a more reliable method to achieve precise leveling across different angles and orientations. This feature is particularly beneficial because even minor misalignments can impact the effectiveness of the radar system, potentially leading to gaps in coverage or compromised detection capabilities. Therefore, understanding the function and quantity of these leveling bubbles is critical for air defense personnel tasked with maintaining and setting up the antenna transceiver group.