Answer:
strVar.replace(pos, n, str);
Explanation:
The strVar.replace() is a javascript function of searching and replacing a string for a defined value, whereby it finds and returns a new string where the defined values are replaced.
For example: to return a string where "Trump" is replaced with "Biden":
We have
var str = "Welcome Trump!";
var res = str.replace("Trump", "Biden", str);
Hence, in this case, the correct answer is strVar.replace(pos, n, str);