Certain oil companies have been called poor corporate citizens because

Some scientific research characterises global warming issue as severe.
Oil companies undermine this research and oppose govt action to limit global warming.
Yet, oil companies spend tons of money in scientific research to address the long term effects of climate change.

This is a paradox. On one hand they undermine research that says global warming is severe. On the other hand they are themselves investing money in how to address issue of climate change (making us believe that they think the issue is severe). How can we explain what oil companies are doing?

A.) The oil companies only recently began investing in scientific research to address climate change issues.

It doesn't tell us that they have stopped opposing govt action and hence have changed their mind recently.

B.) The research dollars invested by the oil companies are specifically earmarked for developing practical technologies that might be used to combat global warming.

Oil companies are investing to make practical tech that will be used to combat global warming. This implies that they are using this money to create future business for themselves. Now it makes sense. Basically, they are against govt regulations so that their profits do not suffer. Then, they are investing their own money in tech that they can sell later to combat climate change. So right now they are creating the problem of climate change and want to continue doing it for the sake of their profits by selling oil and later they will sell their tech to clean up the problem they created in the first place - climate change. So both their actions make sense now.
I do agree that the wording is a little off and it takes a whole lot of effort to realise what it is trying to say.

C.) The government action opposed by the oil companies would negatively impact their profits.

This is why they are opposing govt action, ok. But it doesn't explain why they are investing their own money in climate change research.

D.) The scientific research that characterizes global warming as a severe problem has not been definitively proven.

Doesn't explain that why are they then investing their own money in climate change tech?

E.) The oil companies don't believe that any scientific research related to climate change will ultimately serve their interests.

Then why would they invest their money in research -we don't know.

Answer (B)