Position of Adverb in sentences

I aslo have a following question in TOEIC test" Since Takahashi attends afternoon classes, he_______ the night shift" Answer: A.will be always working B.will always be working C.will be working always D.always will be working
I chose A because adverb is standing after Verb Be and before normal Verb But the right answer is B. Can you help me explain Why?

B. ‘will always be working’ is correct.

When a verbal has more than one component, the adverb is usually placed between the first two, unless an emphasis is meant.

He is always coming late. (usual)
He is coming late, always. (emphasis on ‘he is coming late’)
Always, he is coming late. (emphasis on ‘always’)