Which of the following ingredients is found in high content in rapid hardening cement which results in shortening the final setting time?

Correct option is B

Rapid Hardening Cement: -
Rapid Hardening Portland Cement (IS: 8041) has high lime content and can be obtained by increasing the C3S content but is normally obtained from OPC clinker by finer grinding (450 m2/kg).
The basis of application of rapid hardening cement (RHC) is hardening properties and heat emission rather than setting rate. This permits addition of a little more gypsum during manufacture to control the rate of setting.
RHC attains same strength in one day which an ordinary cement may attain in 3 days. However, it is subjected to large shrinkage and water requirement for workability is more.