[单选题]<img style="max-width: 100%;" src="data:image/png;base64,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" class=""> A <img src="data:image/png;base64,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"> B <img src="data:image/png;base64,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"> C <img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADcAAAAcCAYAAADFsCezAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAGzSURBVFhH7ZjrrcMgDIWZi4GYh2lYhmFcCC9DCNiQextVqdQfbcHw+Rw7VgX88Ev8MBtcwgmxxr267y+S/MJxsvoqx8nWxtpn2tJqkK7mlUFkRoF3RXlL0HZM/iA4C1rGy0sN+N5WSxA1KagIWn3dsH4fLitypYQB3ZMoqiuEAiww5vsSHFJplPqh61KMa3suwJlsCXHYJ30OGRx2y6lKvO5hlLfxTcod3ndel8kmzhpKqaP4U02c4e5QqQcd4w6UJyuXwNpYIXuls2G49jeeLpPVR81dq+Z30+Bi8WbFqg5dW6NnywQ5shAX3MeclSsJ7trb0RqodY8nlFKvvURRAb2LKPvncAPVIDYIfBB1/Eo2F2L+MK6g3ZkUMJotD4DeBfqtmApXLsxoOD7RMy+iTEyVCxk+w+U6aqYJPlx/xDox+CQ3Z4Wdzurd7ykN5WS9kGllYv24W1it8py3Bdc0qgx4mivxjIkeTSvjV+l2PmhUMY8/dfC74NI9S23WQJQBempLagdL6+6G457/gNly58r0va9y9FxNBmdOoBvWvspxkvg2FE62Ntau/fO6ceB/bv0AoCUidqRBk9IAAAAASUVORK5CYII="> D <img src="data:image/png;base64,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">