Q: Americans may become accustomed to the political turmoil swirling around President Donald Trump, but it remains an open question whether that turmoil will ultimately help or hurt Trump and his Republican allies, especially in an election year. Last week, it was Trump's firing of Secretary of State Rex Tillerson and an apparent Democratic victory in a special congressional election in Pennsylvania a sign of a possible wave in the November midterm elections. This week, it was a series of presidential tweets criticizing the Russia probe, followed by a controversial Trump statement of congratulations for newly re-elected Russian President Vladimir Putin. Trump also added former U.S. attorney Joseph diGenova to his legal team. DiGenova has alleged that elements of the FBI and the Department of Justice have been out to frame Trump in connection with the Russia probe. Trump ignored shouted questions Tuesday from reporters at the White House who asked whether he wanted to fire special counsel Robert Mueller, who is leading the Russia probe. Earlier, House Speaker Paul Ryan, a Wisconsin Republican, told reporters at the Capitol that he had received "assurances" that firing Mueller was "not even under consideration." The latest back and forth over the Mueller investigation came after several days of presidential tweets complaining about the probe, including one blasting it as a "total WITCH HUNT with massive conflicts of interest." The tweets sparked new fears that Trump might try to have Mueller fired. Some Republicans warned that an attempt to fire Mueller could put Trump's presidency in jeopardy. "I think anything directed at firing Mr. Mueller blows up the whole town, and that becomes the end of governing and the presidency as we know it," cautioned Republican Senator Lindsey Graham of South Carolina. The renewed focus on the Russia probe came in the wake of last week's firing of Tillerson. That, in turn, raised the prospect of more administration changes. According to the above context, answer the following question. What did Trump criticize in his tweets this week?

Options:
(A). not enough information.
(B). Putin.
(C). the Spanish probe.
(D). the Russia probe.
The answer is:
(D).