Which option below correctly describes the domain of and explains why the range of b is not all real numbers? the domain is all real numbers greater than or equal to 81. the range is not all real numbers because the square root of a negative number is not a real number. the domain is all real numbers greater than or equal to 81. the range is not all real numbers because the square root symbol applied to a non-negative number is non-negative. the domain is all real numbers less than or equal to 81. the range is not all real numbers because the square root symbol applied to a non-negative number is non-negative. the domain is all real numbers less than or equal to 81. the range is not all real numbers because the square root of a negative number is not a real number.