Consider two admissible heuristic functions:
ℎ₁(n) and ℎ₂ (n) for a search problem. Suppose now we define two new heuristic functions: h₁ (n) = h (n) +h₂ (n) /2 ​ and h₄(n) =h₁(n) ⋅h₂ (n) .
a) ℎ₃ (n) and ℎ₄(n) are both admissible heuristic functions.
b) ℎ₃(n) is admissible, but ℎ₄(n) may not be admissible.
c) ℎ₄ (n) is admissible, but ℎ₃(n) may not be admissible.
d) Neither ℎ₃(n) nor ℎ₄ (n) are admissible heuristic functions.