Paco needs at least 3/8 yard of twine to build a model ship. how much twine could he buy?
a. 3/10 yard,
b. 1/4 yard
c. 3/5 yard
d. 1/8 yard.

Minimum length of twine required by Paco to build a model ship = 3/8 yard
                                                                                                       = 0.375 yard.
There are several options already given in the question. We have to check them before reaching a final conclusion.
Option a = 3/10 yard
               = 0.3 yard
So option is less than that reuired and hence cancelled.
Option b = 1/4 yard
               = 0.25
So this option is also less than the length required and hence cancelled.
Option c = 3/5 yard
               = 0.60 yard.
This option looks feasible, but the final option needs to be checked before getting to the conclusion.
Option d = 1/8 yard
               = 0.125 yard
Now we can finally conclude that among all the options given in the question, option "c" is the correct option.