If you learn Japanese... 小麦粉(こむぎこ) is correct. 粉（こな） is definitely wrong. 小麦粉 means a flour. 粉 means a powder. When I listen to 粉(こな) , I come up with many possible powder such feed powder as edible powder and so on. I hope it will be helpful for you^^

both are right，but according to the sentence to distinguish 两个都正确，但需要根据句子意思区分

小麦粉 потому что 粉 это порошок