"about the future" vs. "in the future"

[Leon]

English Language Tests, Intermediate level

ESL/EFL Test #204 "Prepositions of Time and Date (2)", question 10

Someday, ......... the future, we're going to build the house of our dreams.

(a) on
(b) about
(c) in

English Language Tests, Intermediate level

ESL/EFL Test #204 "Prepositions of Time and Date (2)", answer 10

Someday, in the future, we're going to build the house of our dreams.

Correct answer: (c) in

Your answer was: incorrect
Someday, about the future, we're going to build the house of our dreams.
_________________________

why I can't use about

Leon

[Conchita]

'Someday' and 'in (the) future' mean at a time which has not yet happened. It answers the question 'when'.

'About' could be used in phrases like talk or think about the future, for example.