I'd like to add one more explanation to
why D doesn't make senseIn direct speech, the below two scenarios are possible:
1. We expect the increase of piracy as high speed internet connections will become more widely available
2. We expect piracy to increase as high speed internet connections become more widely available
according to which both D and E seems fair. But, if we consider the indirect speech individually,
D. ...they expected the increase of piracy as high-speed Internet connections would become more widely available
Correct usage of would: As water would become widely [Future in the past] available, we can do farming [Referring to future]
Usage in D: As water would become widely [Future in the past] available, we did farming [Referring to past, a construction that is non-sensical]
E. ...they expected piracy to increase as high-speed Internet connections became more widely available
Makes sense as both the events are in past