The correct option is
C spikes
The word, 'piton' refers to '
a peg or spike driven into a rock or crack to support a climber or a rope'. Hence, option B is correct.
A 'spear' is 'a weapon with a pointed tip, typically of steel, and a long shaft'. It is used for thrusting or throwing. 'Hammer' is 'a tool with a heavy metal head mounted at right angles at the end of a handle'. It is used for jobs such as breaking things and driving in nails. 'Harpoon' is 'a barbed spear-like missile attached to a long rope and thrown by hand or fired from a gun'. It is used for catching whales and other large sea creatures.
As the meanings of these three words are different from that of the word, 'piton', options A, C and D are incorrect.