Throughout at the beginning of a sentence?

[Star from Poland]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #98 "The Parliamentary Candidate (1)", question 4

......... the election campaign Henry's wife and his two teenage daughters worked night and day for him

(a) for
(b) throughout
(c) by
(d) from

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #98 "The Parliamentary Candidate (1)", answer 4

throughout the election campaign Henry's wife and his two teenage daughters worked night and day for him

Correct answer: (b) throughout

Your answer was: correct
_________________________

Hi Alan,

Why "throughout" doesn't start with the capital letter?.Also in the previous test my answer was "sand pit" and it was "in red" while it was supposed to be the only correct option. As to the test 47 "raining" is out of question as a correct answer, isn't it? /to agree with Diane./

I appreciate your help, your patience and your great knowledge.

Star from Poland