PURCHASE, New York -- Hillary Clinton was visibly angry at a campaign event on Thursday when questioned by an environmental activist about donations to her campaign from the fossil fuel industry.

While shaking hands with voters during an event at the State University of New York at Purchase, Greenpeace USA activist Eva Resnick-Day asked the if she would reject fossil fuel money.

The question clearly aggravated Clinton, who immediately snapped back. “I am so sick -- I am so sick of the Sanders campaign lying about me. I am sick of it,” she said.

Greenpeace USA subsequently posted the video online. It was shot in partnership with the environmental group 350 Action.

The Sanders campaign fired back at Clinton’s assertion saying that she has taken contributions from lobbyists for fossil fuel companies.

According to FactCheck.org, Clinton’s campaign has not accepted any direct contributions from an oil or gas corporation.

A Greenpeace report found that Clinton has received over $1 million from lobbyists and bunddlers connected to the fossil fuel industry and that her Super PAC has received over $3 million from donors in the industry.

Clinton spokesman Nick Merrill released the following statement in response to Clinton's exchange with the Greenpeace activist. In the statement, he accuses the Sanders campaign of "misleading voters" with its attacks -- and says Sanders has taken $50,000 from oil and gas companies.

"Hillary Clinton has a proven record of leadership when it comes to combatting climate change and has fought against fossil fuel interests for decades. On this campaign, she has laid out tangible, ambitious goals to make America the clean energy superpower of the 21st century and has repeatedly called for eliminating tax breaks for oil and gas companies. The more than one million people who have contributed to her campaign know exactly where she stands on these issues. The simple truth is that this campaign has not taken a dollar from oil and gas industry PACs or corporations. The simple fact is that the Sanders campaign is misleading voters with their attacks. The money in question is from individuals who work for these companies. By the same metric, Bernie Sanders has taken more than $50,000 on this campaign from individuals working for oil and gas companies. Assuming they don’t believe their own candidate is bought by the fossil fuel industry, they should stop the false attacks and do what they’ve claimed the campaign is about: debating the issues.”