Answer: Calligraphy and geometric design
Notes: The representation of living beings in Islam is prohibited. So, in the Indo-Islamic architecture was based on calligraphy and geometrical designs. Indo-Islamic architecture is the architecture of the Indian subcontinent produced by and for Islamic patrons and purposes. Despite an initial Arab presence in Sindh, the development of Indo-Islamic architecture began in earnest with the establishment of Delhi as the capital of the Ghurid dynasty in 1193 CE. Thus, a is the correct answer.
