Given the task definition and input, reply with output. In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Problem: the calendar of the year 2028 can be used again in the year ? 
Options: a ) 2041 , b ) 1951 , c ) 2056 , d ) 1971 , e ) 1973

c