Please explain the process fo solving this

Which one of the logical calculations below takes an arbitrary 8-bit binary input X and clears to 0 its bits at odd positions, leaving its bits at even positions unchanged? Recall, the left most bit is at position 7 , which is an odd bit, and the right most bit is at position 0 , which is an even bit. X AND 10101010 XAND 01010101 X OR 01010101 X OR 10101010