Consider the following method substringFound, which is intended to return true if a substring, key, is located at a specific index of the string phrase. Otherwise, it should return false.
public boolean substringFound(String phrase, String key, int index)
{
String part = phrase. substring(index, index + key. length());
return part. equals(key);
}
Which of the following is the best precondition for index so that the method will return the appropriate result in all cases and a runtime error can be avoided?
A. 0 <= index < phrase. length()
B. 0 <= index < key. length()
C. 0 <= index < phrase. length() + key. length()
D. 0 <= index < phrase. length() - key. length()
E. 0 <= index < phrase. length() - index