题目2单选题
下列碳正离子,存在p -π共轭效应和诱导效应的是A. <img src="https://tihai-oss-cloud.itihey.com/img/150f0d6691ba2b3807965f7475bb9d82.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/ca36186eddb229c3f98a78bb848141f0.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/78c8e1b77a526b9d344202e92139adf1.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/081b0ce702e54f3b9ad8a24fc90adbd4.png">