CEMC Cayley, 2011

Algebra Difficulty 1.0 Junior Find the answer Canada

The operation " $\nabla$ " is defined by $(a, b)\nabla(c, d) = ac + bd$ . For example $(1, 2)\nabla(3, 4) = (1)(3) + (2)(4) = 11$ . The value of $(3, 1)\nabla(4, 2)$ is

(A) $10$ (B) $11$ (C) $13$ (D) $14$ (E) $24$

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