The correct answer is D) Closed cycle. In a closed cycle gas turbine, the turbine exhaust passes through a cooler and is then returned to the compressor inlet, forming a closed loop. This allows the exhaust heat to be recovered and reused, improving the overall efficiency of the system. The other options are incorrect: A) Uni-cycle refers to a single-shaft gas turbine configuration, which is different from the closed cycle described in the question. B) Twin cycle is not a standard term used to describe gas turbine configurations. C) An open cycle gas turbine exhausts the turbine exhaust to the atmosphere, rather than recirculating it back to the compressor.