Unfortunately, Susan Blackwell is finding it

【問題】
Unfortunately, Susan Blackwell is finding it __________ to adjust to the increased responsibility of her new supervisory role.

【選択肢】
1.　hard
http://jibun.atmarkit.co.jp/scenter/ittrain/93_20060620_a1.html

2.　hardly
http://jibun.atmarkit.co.jp/scenter/ittrain/93_20060620_a2.html

3.　hardness
http://jibun.atmarkit.co.jp/scenter/ittrain/93_20060620_a3.html

4.　hardening
http://jibun.atmarkit.co.jp/scenter/ittrain/93_20060620_a4.html

問題提供：リアル・イングリッシュ・ブロードバンド株式会社
http://jibun.atmarkit.co.jp/misc/ct.php?id=TR56_RE1
No.09320060620