题目2单选题
设总体X服从参数为λ的泊松分布,X1,X2,…,Xn是来自总体X的样本,<img src="https://tihai-oss-cloud.itihey.com/img/4f78a90b9c1cf5f198234b153426673a.png">,<img src="https://tihai-oss-cloud.itihey.com/img/aa508bf23cf1aeae53d1ec6fe6bd148f.png">,则下列结论不正确的是( )A. <img src="https://tihai-oss-cloud.itihey.com/img/d32c5fffa6070cf7e8d033d771ff368e.png">是λ的矩估计量,<img src="https://tihai-oss-cloud.itihey.com/img/0b54699644dc42fc7b312a0693e9533d.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/042f635cffd2de2e356153d74984e33e.png">是λ的无偏估计量C. <img src="https://tihai-oss-cloud.itihey.com/img/d32c5fffa6070cf7e8d033d771ff368e.png">是λ的无偏估计量D. <img src="https://tihai-oss-cloud.itihey.com/img/042f635cffd2de2e356153d74984e33e.png">是λ的矩估计量,<img src="https://tihai-oss-cloud.itihey.com/img/667758f6169d32dd210aec0656492b66.png">