Statement:\nIn deserts, camels are indispensable for people to travel from one place to another.\n\nConclusions:\nI. Camels are the only cheapest mode of transport available in deserts.\nII. There are plenty of camels in deserts.

Introduction / Context:
The statement asserts indispensability of camels for desert travel, highlighting suitability and necessity. It does not quantify costs relative to all modes, nor does it estimate population counts of camels. We must judge what follows strictly from indispensability.

Given Data / Assumptions:

• Camels are indispensable for desert travel.
• No premise on relative price vs other modes.
• No premise on the abundance (“plenty”) of camels.

Concept / Approach:
Indispensable means essential/necessary, not necessarily “only cheapest.” The claim “only cheapest” has two qualifiers (“only” and “cheapest”) neither of which appears in the statement. Similarly, indispensability does not imply population sufficiency; there could be scarcity with high demand but still essential use. Thus, neither conclusion is entailed.

Step-by-Step Solution:
1) Interpret “indispensable” as necessity for function.2) Distinguish cost and abundance from necessity → not stated.3) Hence, neither I nor II follows.

Verification / Alternative check:
If camels were expensive yet necessary, or few yet essential, the statement still holds. Therefore, both conclusions add content beyond the given premise.

Why Other Options Are Wrong:
Any acceptance of I or II assumes extra-economic or demographic facts not provided.

Common Pitfalls:
Equating “indispensable” with “abundant” or “cheapest,” which are distinct attributes.

Final Answer:
If neither I nor II follow.