The inequality symbol is “less than,” so it essentially says 16 is less than b/7. You can find the answer simply by substituting your possible solutions into the equation and solving to see if the inequality symbol holds true.
For example, you have an option that says b=63. So substitute b into your equation as so: 16 < 63/7. Since 63/7 can be simplified to 9/1 (9/1 is just 9 because 9 divided by 1 is 9), we can see that this is saying that 16 < 9, which is untrue.
Same thing goes as follows:
16 < 63/7 = 16 < 9 ❌
16 < 70/7 = 16 < 10 ❌
16 < 126/7 = 16 < 18 ✅
16 < 84/7 = 16 < 12 ❌
(Side note: I found the simplified version of a fraction by dividing the numerator (top number) and the denominator (bottom number) by the biggest number that could fit in them both exactly.)
16 < 18 or 126/7 is the correct answer because 16 is less than 18 or 126/7.
I hope this helps, and I apologize in advance if this is wrong. Please ask any questions if you have them.