Option A: $(PS)^+ = {P, Q, R, S, T}.$ So, $PS\rightarrow T$ holds.
Option B: $(R)^+ = {R}.$ So, $R\rightarrow T$ does not hold.
Option C: $(P)^+ = {P, Q, R}.$ So, $P\rightarrow R$ holds.
Option D: $(PS)^+ = {P, Q, R, S, T}.$ So, $PS\rightarrow Q$ holds.