Option 1 -> "by way of" means "through" or "as a means of" - concerns cannot be a method to introduce a law.
Option 2 -> "in accordance with" means "in compliance with" - you don't introduce laws in accordance with concerns; you comply with rules.
Option 3 -> "in the light of" means "considering" or "because of" - correctly indicates the law was introduced as a response to the concerns.
Option 4 -> "on behalf of" means "representing" - used when acting as a representative, not when responding to concerns.
Hence, Option 3: in the light of -> This phrase perfectly conveys that the law was introduced in response to or considering the increasing concerns about public safety, showing the causal relationship between the concerns and the legislative action -> correct