An advantage of the syringe method is that blood appears in the hub when the vein has been entered.
All of these can have a big effect on our food choices.
Let's take product packaging for example - if you're walking down a supermarket, you're more likely to look at and buy a product that looks appealing to you from the moment you see it, not even looking at what that product is or how much it costs.
Product pricing obviously affects your choice as well. If you have the same type of rice from two different producers, you're more likely to buy the one that is cheaper.
Cultural background - this affects perhaps what food we eat. However, given the diversity and possibility, cultural background will have less and less influence. People from an Asian heritage perhaps tend to eat more rice per househould, compared to people from an European heritage. So this may affect how often one would opt for rice or something else instead.
The answer is d all the above
