(A) potassium they contain
(B) bananas are slightly
(C) the natural
(D) radioactive due to

The following question gives a sentence which has been divided into four parts which may not be in their correct order of narrative. The sentence is then followed by five options, one of which gives the sequence of the rearranged parts to make the sentence meaningful. Choose the option which gives the correct sequence of the parts. If the sentence is already arranged in the correct sequence, mark option " No rearrangement required " as the answer.

The correct option is BDCA.

Let's step-by-step rearrange the given sentence fragments to form a grammatically correct and coherent sentence:

1. Part (B): "bananas are slightly"
This serves as a natural subject and verb phrase to begin the sentence.

2. Part (D): "radioactive due to"
This appropriately follows "slightly" to describe the state or property of bananas ("bananas are slightly radioactive due to...").

3. Part (C): "the natural"
This prepositional continuation describes what causes the radioactivity ("due to the natural...").

4. Part (A): "potassium they contain"
This completes the noun phrase describing the natural element ("...the natural potassium they contain").

Combining these parts in the order B → D → C → A gives the complete, meaningful sentence:

"Bananas are slightly radioactive due to the natural potassium they contain."

Therefore, the correct sequence is BDCA.