A、Aircraft. B、Boat. C、Nearby cargo ship. D、Vessels at the oil rig. C细节推断题。虽然无法参与救援，但根据aircraft can’t be used to rescue the crew，

A Russian cargo ship with about 30 crew members was in danger of sinking off Russia’s eastern coast while bad weather interfered with rescue efforts, state-run Itar-Tass news agency said Friday.
    Ice had formed on the outside of the ship and the crew was trying to solve the problem. The crew sent out the signal but there was no explanation of the problem. Because of the bad weather aircraft can’t be used to rescue the crew. According to Itar-Tass the vessel is about 19 miles from the oil rig where rescue vessels are based, while a boat departing from land were still about 4 times farther away. "The cargo ship had been on route to a fishing area when it experienced problems." The news agency reported, "The ship transfers fish from boats to ports."
3. The Russian cargo ship was sinking. What was the direct cause?
4. Which of the following was NOT mentioned as a possible means of rescue?