For a complex number written in the form a + bi, a is called the real part of the complex number and b is called the imaginary part. The sum of two complex numbers, a+bi and c+di, is found by adding real parts and imaginary parts, respectively; that is, (a+bi)+(c+di)=(a+c)+(b+d)i. Therefore, the sum of 2+3i and 4+8i is (2+4)+(3+8)i=6+11i. Choice A is incorrect and is the result of disregarding i and adding all parts of the two complex numbers together, 2+3+4+8=17. Choice B is incorrect and is the result of adding all parts ofthe two complex numbers together and multiplying the sum by i. Choice D is incorrect and is the result of multiplying the real parts and imaginary parts of the two complex numbers, (2)(4)=8and(3(8)=24, instead of adding those parts together.