想要统计数字1在列表number中出现的次数，正确的代码是？（ ）

n = 0
for i in range(len(number)):
if number[i] == 1:
n += 1
print(n)

n = 0
for i in range(len(number)):
if i == 1:
n += 1
print(n)

n = 0
for i in range(number):
if number[i]==1:
n+=1
print(n)

n = 0
for i in range(len(number)):
n+=1
print(n)