Job B with 25 percent more pay may not be that much of a difference initially, but down the line if this difference turns into a wider gap, say 100%, (which is very possible as starting salary has a huge impact on future earning potential) then Job B will be a better choice, at least from financial security perspective.
Out-of-school salaries for the first few years is pretty important (at least for engineering) for earning potential down the line, someone starts out at 75k will hit 100k in 2-4 years. Someone starts out at 45k may take as many as 10 years to hit 100k, if ever.
Present money > future money. 100k at 25 years old > 100k at 35 years old, the sooner you have more disposable income the sooner you can start investing. It takes money to make more money. So the starting point may affect earning exponentially down the line.
Of course, we are only talking about the money perspective. There are definitely people don't give a shit about money and lives perfectly happy on 25k. But for the majority of us, we need money to be happy and provide for those people that we love.