the answer is (d), since we can show equivalence between LT and CFL's and between LR and CFL's:

LT and CFL's:

Each normal PDA is a T machine (we don't care about the stack, so it can be empty).

Each T machine can be converted to a "normal" PDA - we add to each receiving state of the T machine a state to empty the stack, and when it's empty we sent it to a receiving state.

LR and CFL's:

Each R machine can be converted to a "normal" PDA - we just split the states so that one transition that pushes two symbols becomes two transitions, each pushing one symbol.

Each "normal" PDA can be converted to a R machine - we dedicate a special symbol, # e.g, and each time insert it with the symbol we wanted to insert. we can then pop it and get the next symbol.

that's why LR=CFL=LT

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