The correct answer here is A. The Senate did not vote to convict President Clinton on the charges that were levelled against him. A majority of the Senate voted to convict on one charge and 50% of the Senate voted to convict on the other, but a two-thirds majority is needed. This is why B is not correct.
The House does not vote on whether to convict a president who is impeached. The House votes on whether to charge the president--to impeach him. However, it is the Senate that votes on whether to remove the president from office. This is why A is correct and D is not.