[Grammar] Future perfect/ Passive voice (wrong question in my book?)

[SirGod]

I've been doing a lot of English grammar tests, and I've just come across this question:

By the year 2050 new drugs ... which ... people's fight against cancer.

a) will have discovered/ will help
b) will be discovered/ will be helping
c) shall be discovered/ may help
d) would be discovered/ would help

The problem is that no answer seems to fit perfectly. We use future perfect with by the year so the only choice is a). Shouldn't be the first answer like this (passive voice):

a) will have been discovered/ will help

Am I wrong?

 

[5jj]

By the year 2050 new drugs ... which ... people's fight against cancer.

a) will have discovered/ will help
b) will be discovered/ will be helping
c) shall be discovered/ may help
d) would be discovered/ would help

The problem is that no answer seems to fit perfectly. We use future perfect with by the year so the only choice is a). Shouldn't [STRIKE]be[/STRIKE] the first answer be like this (passive voice):

a) will have been discovered/ will help

You are right.

However, just as some speakers are not too particular about using the past perfect when they 'should' use it, so some do not always use the so-called 'future perfect' when careful speakers might. I could just about accept will be discovered in the main clause, though I don't like it - but only with will help in the relative clause. If we use will be helping in the relative clause, then we are talking about a situation that has already begun - it demands will have been discovered in the main clause.