I did a 3 second google search for "tim o'brien" and the first thing that came up was the novel he wrote about the vietnam war called "The Things They Carried" written in 1990.
Pretty sure the answer is stiffness. Hope this helps.
<h2>Answer→↓</h2>
<em><u>Obsessive</u></em>
<em><u>Obsessive√</u></em>
<em><u>Symmetrical×</u></em>
<em><u>Impinging×</u></em>
<em><u>Thanks </u></em><em><u>to </u></em><em><u>my </u></em><em><u>obsessive </u></em><em><u>desire </u></em><em><u>to </u></em><em><u>finish </u></em><em><u>the </u></em><em><u>book.</u></em>
<em><u>100%</u></em><em><u> </u></em><em><u>correct </u></em><em><u>answer</u></em>
<em><u>not </u></em><em><u>nonsense</u></em>
<em><u>Philippine's </u></em><em><u>brainly </u></em><em><u>helping </u></em><em><u>student</u></em>
<em><u>TYSM^</u></em><em><u>^</u></em>
the mood is suspenseful because the reader is not sure when Montresor is going to kill Fortunado.