I have a feeling you're looking for Microsoft Outlook.
Any end tag in HTML needs to look like this, the word body used in this example is one of the more important elements, but you can replace it to any real element in HTML:
i.e. </body>
Depends on what you are working on.
If you are working on a website I recommend Adobe Dreamweaver CC.
if its small assignments that doesnt involve major work, I'd use something like notepad++
Answer: The correct answer is to look up the unfamiliar words in a dictionary or online.
Explanation: When using context clues to better understand reading, Marlene will first read around the unfamiliar words, looking for clues before and after the unfamiliar words. If she still does not know the meaning of an unfamiliar word her next step is to look up the word in a dictionary or online.