Usage of "would" and "will"

[aspirant2011]

Answer should be D only because "would" represents more certainity than "will" and "could" represents less certainity than "can"...............SC says that majority believe but they are not sure therefore a combination of will and could should be used in the sentence........................would and could when used in the same sentence is an orthodox thing and should never be used..............

[Jim@Grockit]

would and could when used in the same sentence is an orthodox thing and should never be used..............

I am not sure what you mean here -- the sentence "I can and will beat the GMAT" in past reported speech would be "Jim said that he could and would beat the GMAT."

In any event, one doesn't use "would" of predictions you think are likely; in addition to being the past tense of "will", it is a modal verb used for conditional statements and predictions that re unlikely (If I did win the lottery, I would quit my job).

Also, "will be or could become" works because the comma is part of the underlined phrase and is removed by choice D. If we had to keep the comma after "could", it would be bad.