(A) The quality of child care will improve.
We can't infer this as we have no idea from the passage what will happen to child care once it is regulated by the government so inferring this will be a jump.
(B) The cost of providing child-care services will increase.
We can infer this we are given that government is certain to respond to this and certainty means it is going to happen for sure. We are given in the argument "governments inevitably make the activity more expensive by regulating it" so this option logically flows from the given info.
(C) The government will use funding to foster advances in child care.
We can't infer this as clearly we don't have any info on this front from the passage.
(D) If public criticism of policy is strongly voiced, the government is certain to respond.
This option is an eye-catcher but we don't know whether the policy is socially necessary or not.
(E) If child-care services are not regulated, the cost of providing child care will not increase.
We can't infer this as regulation of socially necessary service (child care service in this case) is not the only way for an increase in costs, there can be other ways like corrupt medical system, etc.