Solution:(d) The guard said, "Children, stay away from the flower beds." (Correct)(a) The guard says to the children, "Stay away from the flower beds." (Incorrect Reporting Verb)
(b) The guard told to the children, "Stay away from the flower beds" (Incorrect Reporting Verb)
(c) The guard said, "Children, should you stay away from the flower beds." (Incorrect Words)