The correct answer is: a) Shivalik Hills.
The Shivalik Hills are a mountain range in northern India and Pakistan. They are part of the Himalayan foothills and are composed of sedimentary rocks that were deposited during the Tertiary period. The Shivalik Hills are the oldest geological formations in Punjab.
The Indo-Gangetic Plain is a vast plain in northern India and Pakistan. It is formed by the alluvial deposits of the Indus and Ganges rivers. The Indo-Gangetic Plain is a relatively young geological formation, having been formed during the Quaternary period.
The Aravalli Range is a mountain range in northwestern India. It is the oldest mountain range in India, having been formed during the Precambrian period. The Aravalli Range is not located in Punjab.
The Thar Desert is a desert in northwestern India and eastern Pakistan. It is the largest desert in India and the second largest desert in Asia. The Thar Desert is not located in Punjab.