Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the correct order to form a meaningful and coherent paragraph.
A. However, physical fitness and a stubborn fearlessness never let a climber fail.
B. The equipment can be made so light that no extra energy is spent in carrying it.
C. To a large extent, the physical difficulties can be reduced by paying attention to the equipment.
D. It is certain that weather plays an important part in the success or failure of mountain climbers.

Let's analyze the links between sentences to find the correct logical order:
Sentence D introduces the main overarching topic: factors governing the success or failure of mountain climbers (specifically, the role of weather). This serves as an excellent opening sentence.

Sentence C transitions from general difficulties to how "physical difficulties can be reduced by paying attention to the equipment."

Sentence B elaborates directly on the "equipment" mentioned in C, stating how it can be made light so no extra energy is spent carrying it. This forms a mandatory pair (CB).

Sentence A begins with the contrastive conjunction "However" and provides the final concluding thought—that despite external factors like weather or equipment, a climber's inner physical fitness and stubborn fearlessness ensure success.

Thus, the logical arrangement is DCBA.