How were martin luther's criticisms of the catholic church similar to those of john calvin?

a. both men believed that only adults should be baptized.
b. both men believed that the catholic church must be reformed gradually from within.
c. both men believed that the catholic church should end the sale of indulgences.
d. both men believed that a person's nationality was more important than his religion.

Both men believed that the Catholic Church should end the sale of indulgences. Option C is correct.

An indulgence is a pardon for certain types of sin. The Catholic Church sold indulgences in the late medieval period, and their sale motivated Martin Luther to present his "95 Theses, "which was a document created in 1517 to attack the Catholic Church’s corrupt practice of selling “indulgences” to absolve sin.  

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.

determination