Question

an asynchronous binary up counter, made from a series of leading edge - triggered flip - flops, can be changed to a down counter by taking the output on the other side of the flip - flops (instead of q) clocking of each succeeding flip - flop from the other side (instead of q) changing the flip - flops to trailing edge triggering all of the mentioned none of the above

Explanation:

In an asynchronous binary up - counter made of leading edge - triggered flip - flops, to convert it into a down counter, clocking each succeeding flip - flop from the $\overline{Q}$ (the other side instead of $Q$) is the correct approach. Taking the output from the other side of flip - flops doesn't change the counting direction. Changing to trailing edge triggering also doesn't convert it to a down counter.

Answer:

B. Clocking of each succeeding flip - flop from the other side (instead of Q)