To solve this problem, we need to find the odd pair of numbers from the given options based on a specific pattern or rule followed by the majority of the options. Let's examine each pair:

• 43-6: The digits of 43 add up to 4 + 3 = 7, but there is no direct multiplication or addition/subtraction pattern linking 43 to 6.
• 28-4: The digits of 28 add up to 2 + 8 = 10; however, dividing or subtracting still doesn't directly relate 28 to 4.
• 50-7: Here, the digits of 50 add up to 5 + 0 = 5, which can be considered as subtracting 3 for the second number, 7.
• 36-5: The digits of 36 are 3 + 6 = 9, which seen differently does not provide a direct link to 5 without an alternate pattern.

To determine a pattern, observe that when you subtract the smaller number from the larger number:

• 43 - 6 = 37
• 28 - 4 = 24
• 50 - 7 = 43
• 36 - 5 = 31

The odd pattern stands out. Unlike the others where larger elements don't subtract to a double-digit number directly relatable through common subtraction arithmetic, 28-4, within the given combinations, doesn't align as easily or intuitively within the subtractive framework. This identifies it as the anomaly.