A. Touch iii. Sensory papillae

Explanation: The sensory papillae in frogs have the touch receptors in them which are used for the reciprocating the sense of touch in frogs.

B. Smell i. Nasal epithelium

Explanation:Nasal epithelium has smell receptors i.e., olfactory receptors which help in the sensing of the smell of a particular substance.

C. Cranial nerves iv. Peripheral nervous system

Explanation:The nervous system consists of two divisions: Peripheral nervous system (PNS) and Central nervous system (CNS). Cranial nerves are a part of the peripheral nervous system. Cranial nerves have further divisions for different nerves which help in sight, smell, etc.

D. Medulla oblongata ii. Foramen magnum

Explanation: Foramen magnum helps in the transmission of medulla oblongata membranes. The Foramen magnum is the passage for connecting the brain and spinal cord.