Etruscan was first written
a. in the first century bc.
b. about 280 bc.
c. between 700 and 699 bc.
d. around 800 bc.

The oldest finds with Etruscan language come from around 700 BC - so in any case A and B are false: they are too late.

Now, 800 BC is a little too early, 700 is better, but we don't know that specifically that it was " 700 and 699 BC" - are you sure that this is the actual option? this gives a span of only one year... I still think that it's the best answer though. 

Ais your answer