Answer:
C.) I'm worried, Sandra that your book is lost.
Step-by-step explanation:
In the first option, there is no comma beside "Worried". There should be one there, which means that can't be correct.
Then the second one has 2 commas. There shouldn't be one beside "Sandra". Therefore that option isn't correct.
That leaves the third one. There's a comma beside "Worried". This is the correct option.
Hope this helps!