There is nothing wrong, grammatically, with option D. It is not the correct answer because it is hard to imagine why somebody would ever say that they wanted "to be equal to other things". "All other things being equal" is a common expression. In it, the meaning of "equal" is "unchanged". Thus it means "all other things remaining unchanged from what they now are". The expression has Latin equivalent, "ceteris paribus" (normally in italics) that is commonly used: "Ceteris paribus, a man who expresses himself efffectively is sure to succeed more rapidly that one whose command of language is poor." The meaning is that unless some change prevents it from happening, he is sure to succeed. Look up "ceteris paribus" on the web. You will find long lists of examples.

Option "D" is not the familiar phrase. Option "C" is commonly used. Other phrases like this would be; "As long as you know..." "In keeping with..." "As far as I'm concerned...."