Use a Truth Table to Answer the Following Question $$\frac { \mathrm { R } \equiv \mathrm { T } } { \mathrm { R } }$$

Use a truth table to answer the following question.Which, if any, set of truth values assigned to the atomic sentences shows that the following argument is invalid? $$\frac { \mathrm { R } \equiv \mathrm { T } } { \mathrm { R } }$$

A) R: T T: T
B) R: T T: F
C) R: F T: T
D) R: F T: F
E) None-the argument is valid.