1. Which one of the following is a work attributed to playwright Bhasha?

Bhasha (Bhāsa)
One of the earliest and most famous Sanskrit playwrights (often placed before Kālidāsa). A number of classical Sanskrit plays are traditionally attributed to him.

“Work attributed to”
In ancient Indian literature, authorship is sometimes based on later tradition and manuscript transmission, so the question is asking which title is known as a Bhāsa play.

(a) Kavyalankara

A term used for poetics/ornamentation treatises (alaṅkāra-śāstra). The famous Kāvyālaṅkāra is associated with Bhāmaha (and other “kavyalankara”-titled works with later theoreticians), not Bhāsa.
❌ Not Bhāsa.

(b) Natyashastra (Nāṭyaśāstra)
The foundational Indian text on dramaturgy, traditionally attributed to Bharata Muni, not Bhāsa.
❌ Not Bhāsa.

(c) Madhyama-vyayoga (Madhyamavyāyoga)
A Sanskrit play belonging to the vyāyoga type, and it is attributed to Bhāsa.
✅ This matches Bhāsa.

(d) Mahabhashya (Mahābhāṣya)
The great Sanskrit grammar commentary by Patañjali, not Bhāsa.
❌ Not Bhāsa.