Answer:
a. Dona sent the letter.
b. Melodi received the letter.
c. The letter was written the 5th of October 2017.
d. Dona's personal letter is an informal letter.
e. The main idea of the text is to inform the recipient of his departure and bid the recipient goodbye.
Step-by-step explanation:
From the letter, it's very clear that Dona sent the letter because Dona's name is seen at the closing remark of the letter. Melodi is the recipient (receiver) of the letter because the name appeared at the introductory/salutation part of the letter.
The date it was written was clearly stated in the letter and it is at the top right hand side of the the letter.
Informal letters are known to be the type of letters that are written to friends, acquaintances, relatives, etc., in order to pass an information, send greetings and interact.