Should I change my datastructure (specifically the questions-table) for online examination by the following tbales

Guys i have planned to do an application online examination.i need in help of table structure, kindly suggest me a better tale structure

my objective is iam an organization. i will bukly add questions and answers for online quiz examination and store it in db for later writing exams. i will explain my db structure.

my EduationStandardtable with fields

id  standard_name
1   CBSE
2   ICSE
3   Matriculation
4   State board

my classDetailstable with fields

id  class_name
1   5th std
2   6th std
3   7th std

my SubjectDetails table with fields

id  sub_name
1   english
2   maths
3   physics

Education standard is related to subjects in many to many relationship. class is related with subject with many to many relationship.

my ChapterDetails table with fields

id  subject_id      ChapterName
1   1               Matrices
2   1               Integration
3   1               Differentiation
4   3               Electrostatics
5   3               Tranformation
6   3               Electricity

my TopicDetails table with fields

id  chapter_id          Topic_id
1   1              Inverse of a Non-Singular
2   1             Elementary Transformations of a Matrix
3   1           Solving System of Linear Equations
4   4           Role of electrostatic
5   4           Electric flux
6   4           Polaraisation

subject has chapters with one to many and chapter has topics with one to many. So I planned to have my question table like this,

id
education_standard_id(fk)
class_id   (fk)
subject_id (fk)
chapter_id (fk)
topic_id (fk)
level (easy,medium,hard)
question_number
question_description
question_image(optional)
optionA:
optionA_image:(optional)
optionB:
optionB_image:(optional)
optionC:
optionC_image:(optional)
optionD:
optionD_image:(optional)
correctanswer
explanation
explanation_image (optional)
explanation_pdf (optional)
explanation-video(optional)

Is this enough? How else can I optimise this.

totally five tables class-table, subject-table, chapter -table, topic-table, question-table

is this format right?? else do i need to change.

via Chebli Mohamed