Which light pattern has a 20-meter distance between the left and right stem lights?

• A. Inverted Y
• B. Circle
• C. Cross
• D. T

Answer: (D)

The pattern being described is the T pattern. In this configuration, there are two lights forming a horizontal top bar (left and right) with a fixed distance between them, and a third light centered below to complete the stem, creating the letter T. The 20-meter separation specifically matches the distance between the two top lights in the T pattern, which is why this option is correct. Other patterns don’t have that same fixed left-right spacing: an inverted Y forms a Y-like shape, a circle places lights around a loop, and a cross uses four lights at different positions—none define a precise 20-meter gap between a left and right top pair.