Read the sentence to find out whether there is any grammatical or idiomatic error in it. The error, if any, will be in one part of the sentence. The letter of that part is the answer. If there is ‘No error’, the answer is (5). (Ignore errors of punctuation, if any). Except for causing of episodic mortality of pinnipeds and cetaceans in Europe and North America, the virus had not spread to marine mammals.