Look at the $$KL$25$Z$$ manual in chapter $24$ on the Multipurpose

Clock Generation module $($MCG$).$

This module is very important for setting up the various clocks used on the chip: It has both Phase Locked Loop and Frequency Locked Loop. It also has built in very accurate reference clocks. Read through the chapter $24$ in the KL$25$Z data sheet and answer the following questions:

a$.$ How many internal reference clocks are there and what are their frequencies?