Question Analysis:

The given question follows an analogy format, where we are asked to find the relationship between two words and then apply the same relationship to find the missing word. In this question, we need to identify the relationship between "Safe" and "Secure" and then find the word that has a similar relationship with "Protect". Let's break down the relationship between "Safe" and "Secure".

Relationship between "Safe" and "Secure":

The word "Safe" is related to "Secure" in the sense that "Secure" is a stronger and more intense version of "Safe". When something is safe, it means it is free from harm or danger. Similarly, when something is secure, it means it is protected or free from danger. Therefore, the relationship between "Safe" and "Secure" is that "Secure" is a stronger form or synonym of "Safe".

Applying the Relationship:

Using the relationship we identified between "Safe" and "Secure", we can apply it to the word "Protect" and find the alternative that has a similar relationship with it. Among the given options:

a) Lock - Lock is not a stronger or more intense version of "Protect". It does not have a similar relationship as "Secure" has with "Safe".

b) Sure - "Sure" does not have a similar relationship as "Secure" has with "Safe".

c) Guard - "Guard" is a stronger and more intense version of "Protect". When we protect something, we are keeping it safe or free from harm. Similarly, when we guard something, we are watching over it and protecting it from any danger or harm. Therefore, "Guard" is the alternative that has a similar relationship with "Protect".

d) Conserve - "Conserve" does not have a similar relationship as "Secure" has with "Safe".

Conclusion:

Based on the relationship between "Safe" and "Secure", we can conclude that the alternative which will replace the question mark is "Guard" (Option C).