Answer:
Option: A. To serve as a mausoleum for his wife.
Step-by-step explanation:
Shah Jahan of the Mughal Empire built Taj Mahal as a mausoleum for his wife, Mumtaz Mahal. After the death of Mumtaz Mahal in 1631, he ordered to build a building across the Yamuna River from his royal palace at Agra. The construction of Taj Mahal began around 1632 and continued till two decades. Workers from India, Europe and the Ottoman Empire were brought to build this magnificent structure. The mausoleum was built using white marble along with semi-precious stone like jade, lapis lazuli, crystal, amethyst and turquoise.