Read the following article and answer the question by choosing from the options.

There was a book tucked in there , but she was n't sure she could afford not to keep an eye on Roy right now . With a sigh , he flopped down on the seat beside her . Riza snuck a glance at his face . He looked defeated and worn out."Hawkeye ? " " Yes , sir ? " " Come here a moment . " He tugged her into his lap , wrapping his arms around her waist and burying his face in her shoulder . Riza gently stroked his hair . " Promise me you 'll be careful . " His voice was muffled by her shirt .

Why did she want him to be careful ?
Select from:
(a). None of the above choices ..
(b). She could not afford not to keep and eye on him due to the book ..
(c). She was afraid that someone would give the book to Roy ..
(d). He was going to do something dangerous and could get hurt .....A:
(d).