Which code corresponds to the description 'Signal can clear relay light on interlocking machine'?

• A. GK
• B. HV
• C. HE
• D. HGT

Answer: (C)

When thinking about interlocking machine operations, each code marks a specific control action related to the relays and signal lights. The description “Signal can clear relay light on interlocking machine” points to the action of releasing or resetting a relay light so the signal can proceed or be considered clear.

The code that matches this clearing or releasing action is the one assigned to that exact operation—clearing the relay light. That’s why the code corresponding to this description is the correct choice. The other codes describe different actions or statuses on the interlocking system, which do not fit the scenario of clearing the relay light.