Which of the Following Changes Is I) a Synonymous Mutation $\rightarrow$

Essay

Which of the following changes is i) a synonymous mutation, ii) a conservative substitution, iii) a nonconservative substitution, iv) a stop-loss mutation, v) a stop-gain mutation.
a) UGA $\rightarrow$ UCA
b) UAC $\rightarrow$ UAA
c) AGA $\rightarrow$ AAA
d) AGA $\rightarrow$ CGA
e) UGU $\rightarrow$ CGU