What it means 'dim'?

[Luda from Minsk]

English Language Tests, Intermediate level

ESL/EFL Test #216 "Antonyms (2)", question 7

The dim lights made it hard to see, so Ben squinted to make out the stranger's face in the distance. What is an antonym of 'dim'? .........

(a) faint
(b) muted
(c) strong
(d) weak

English Language Tests, Intermediate level

ESL/EFL Test #216 "Antonyms (2)", answer 7

The dim lights made it hard to see, so Ben squinted to make out the stranger's face in the distance. What is an antonym of 'dim'? strong

Correct answer: (c) strong

Your answer was: incorrect
The dim lights made it hard to see, so Ben squinted to make out the stranger's face in the distance. What is an antonym of 'dim'? muted
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Could you explain, what it means 'dim'

Luda from Minsk(BELARUS)

[Skrej]

'dim' means not very bright.
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