Answer: Both X and Z.
Explanation:
Spring tides are high tides which occur when the Sun, the Earth and moon line up in one straight line. The effect of gravity is maximum in this position and hence, causes high tides.Thus, the coastlines X and Z experience high tides and W and Y coastlines experience low tides. The spring tides have highest high tides and lowest low tides unlike Neap tides.
Thus, in this current position, coastlines which are experiencing the high spring tides are X and Z.