**Explanation:**

When we add -ing to a verb, it usually forms the present participle of the verb. The present participle is used to indicate an ongoing action or state. In this case, the verb "try" is being transformed into its present participle form.

The correct answer is option 'A' - Trying. Let's understand why:

**Adding -ing to the verb "try"**

When we add -ing to the verb "try", we get "trying". This is the correct form of the word because it follows the rules of English grammar.

**The meaning of "trying"**

The word "trying" is derived from the verb "try" and it has several meanings. It can mean making an effort, attempting, or endeavoring to do something. For example:

- She is trying to solve the puzzle.
- He is trying his best to pass the exam.
- The team is trying to win the match.

**Other options and why they are incorrect**

b) Tring - This option does not follow the rules of English grammar. When adding -ing to a verb, we generally keep the original spelling intact and add the -ing suffix. Therefore, "tring" is not a valid word.

c) Triyng - This option also does not follow the rules of English grammar. The base verb "try" does not have a "y" in its spelling, so adding a "y" in the -ing form would not be correct.

d) Tryng - This option is incorrect for the same reason as option 'b'. The base verb "try" does not have any missing letters that need to be added when forming the -ing form.

**Conclusion**

The correct word formed by adding -ing to the verb "try" is "trying". This is the present participle form of the verb and it is used to indicate an ongoing action or state.