By the time the forest fire .............

[Volcano1985]

By the time the forest fire ............. in autumn 1988, the Yellowstone National Park .............. with being consumed flames.

A) has been harnessed / will have been threatened
B) was being harnessed / had threatened
C) had been harnessed / had threatened
D) harnessed / has threatened
E) was harnessed / had been threatened

I think E

[Ann1977]

By the time the forest fire ............. in autumn 1988, the Yellowstone National Park .............. with being consumed flames.

A) has been harnessed / will have been threatened
B) was being harnessed / had threatened
C) had been harnessed / had threatened
D) harnessed / has threatened
E) was harnessed / had been threatened

I think E

Me too.