SITUATIONS given, \[a\times b\,\THETA \,c\]mean \[aPHI \,c\] MEANS \[a\,>\,b\,\ne \,c,\] this is not true. From option (b), \[a+b\,\theta \,c\] means \[a\,\LE \,b\,=\,c,\] this is true. From option (c), \[a\,\phi \,b\,\theta \,c\] means \[a\ne b=c\] this is true From option (d), \[b\,\theta \,c\,\square \,a\] means \[b=c\ge a,\] this is true So, the answer is (a).