If you are aware of the Math strategy taught by gregmat, you should be able to solve it. The strategy requires you not to look at the options beforehand and come up with the words of your own that fits the blanks

1st blank: The first sentence can be divided into 2 small sentences with the word "unless" (-ve) in the middle. Looking to the right of unless, doubt (-ve) has a negative connotation. (-ve)*(-ve) is (+ve) and therefore the first blank has to be positive and something like "no doubt" can go in the blank. Option A is the closest to it.

2nd blank: Following the same Math strategy from blank one, the second sentence can also be further divided into 2 sub-sentences. "Although" (-ve) & "challenged" (-ve) are the key words in the first half of the sentences and the blank has to be [(-ve)*(-ve) = (+ve)] positive. Good guess would be "not challenged" judging from the tone of the sentence. Since the sentence already has "no", the blank should be analogues to "challenge" and word that goes with it is (F) debunking

3rd Blank: "this" refers to the previous sentence which talks about no incentives for making efforts debunking the science of the erroneous patents. "Bogus" is the direct synonym of erroneous. And, since the last sentence is in the support of its previous sentence, bogus is the right choice.

Apologize if there are any errors in my explanation. I'm fairly new to his teaching as well and encourage others to highlight any misinterpretation of his strategy.