Correct : b

In the given code examples (IMAGE → FHBNJ and FIELD → EMFJG), the letter shifts vary in each position, with a mix of positive and negative changes rather than a single fixed shift. This means that each position in the word may have its own coding rule.

To find the code for BEACH, we test each option letter by letter to see which matches the shifting style of the examples.

Testing option (d) IBCEC:
B(2) → I(9) = +7 shift
E(5) → B(2) = -3 shift
A(1) → C(3) = +2 shift
C(3) → E(5) = +2 shift
H(8) → C(3) = -5 shift

This pattern of mixed positive and negative shifts (+7, -3, +2, +2, -5) is consistent with the variations seen in the given coded words, especially the ending shift of -5 which appears in the examples.

✅ Final Answer: Option (d) — IBCEC.

Reason: Among all choices, IBCEC matches the irregular positional shift pattern style used in the provided code examples.