Select the most appropriate option to fill in blank number 1.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. knowing.
"Knowing" fits because the sentence emphasizes the importance of understanding first aid measures.
"Knowing" means having awareness or understanding of something.
Meaning of the other options:
Regarding: Concerning or relating to something.
Attempting: Making an effort to do something.
Before: Earlier than something in time.
Hence, the chosen option is correct.