Укажи схему реакциидегидратации:

• \(C_{2}H_{5}OH + O \rightarrow CH_{3}CHO\)
• \(C_{3}H_{6} \rightarrow C_{3}H_{4} + H_{2}\)
• \(C_{2}H_{5}OH \rightarrow C_{2}H_{4} + H_{2}O\)
• \(C_{3}H_{4} + H_{2} \rightarrow C_{3}H_{6}\)