Directions: Select the phrase from the options below that should replace the underlined phrase in the sentence to make it grammatically and contextually correct. If the sentence is already correct, select 'No correction required' as your answer.
Data accumulated during service operation will allow the companies to make constantly vehicle improvements to better meet local needs and specifications.
1
make constant to
2
to make constant
3
to made constant
4
constantly make
5
No correction required