First of all, CITE YOUR SOURCE. It's a copyright violation to print questions without crediting the writer.

Secondly, you're not quite approaching the WEAKEN question in the right way.

Our goal with a weaken question is not to CONTRADICT the conclusion or prove it wrong. Our goal is to DISRUPT THE LINE OF REASONING: to add information that suggests that the premises given do not fully support the conclusion.

Premise: applications that allow people to block advertisements have been gaining popularity among the users of drench.com.

Conclusion: to prevent any further decrease in the revenues, drench.com must ban such applications from running on its website.

Unstated Assumption: there is no other way to prevent decreases in revenue than to ban these applications.

In order to WEAKEN, we must find information that suggests that there might be some other way to prevent revenue loss.

our aim is to weaken it.
posibilities that we can think of.
1. drench guys are worried without any reason, as there is no proof for their worries. actually people are not using such thing for drench.

This is not how we should approach a weaken question - the right answer will almost never contradict a given premise. If we're told that drench.com users are using these applications, take that as fact.

2. people love to watch ad on drench. or in genral they disable their ad bloker and enable it when they really need it.

That's a possible explanation.

C. The website can easily charge the users for using such applications to compensate for any loss of advertisement revenue. --- lets assume website is drench, they are getting revanue when someone click those ads, not just looking at them. so what is the point of charging if most people just look at those ads and walk away. more over what if people start walking away from drench and go for some alternative site .

We don't have to prove that every user will click on the ads. If revenue is generated from clicking on ads, and many users block ads from being seen, then it stands to reason that charging users to use blockers will either a) generate revenue from those who agree to pay, or b) some of the users who agree to disable the ad-blockers will click on some of those ads, generating revenue.

D. Most of the website visitors who use the advertisement-blocking applications would have found the information in the advertisements quite useful. --- this seems more close to our line of thoughts. if so drench guys should not be worried.

How does this WEAKEN the link between "ad-blockers are increasing in popularity" and "drench.com must ban ad-blockers to prevent revenue loss"? This is telling us that people aren't going to see ads that they might otherwise have found useful. But if they're not seeing them, it won't impact revenue. This does not suggest that users KNOW that these ads are useful, or that they would WANT to turn off their ad-blockers for that reason.

Does that help?