The question asks about the types of trees commonly found on the slopes of Morni Hills. Let's evaluate each option based on their presence in this region:

1. Eucalyptus and Sal: While Eucalyptus trees might be found in various regions in India, the combination with Sal is more typical of forest regions. Morni Hills, being part of the Shivalik range, does not primarily feature these trees.
2. Deodar and Cedar: These trees are generally found in higher altitudes, such as in the Himalayas, and are not native to the Shivalik ranges, where Morni Hills is located.
3. Bamboo and Teak: Bamboo might be found in various parts of India, but teak is more typical in central and southern India rather than the Shivalik range.
4. Neem, Oak, Pipal, and Jacaranda: These trees are well-suited to the climatic conditions of the Morni Hills area, making them the most likely correct answer. Neem is common across India for its medicinal properties, Oak and Pipal are native to various hill regions, and Jacaranda, which is often planted for its beautiful flowers, can thrive in this environment.

Considering these points, the option "Neem, Oak, Pipal, and Jacaranda" is the most appropriate answer, as these are typical of the landscape and climate of the Morni Hills region. Hence, the correct answer is: